title: Metal-free carbon-carbon bond-forming reductive coupling between boronic acids and tosylhydrazones.
abstract: The formation of carbon-carbon bonds is a fundamental transformation in organic synthesis. In spite of the myriad methods available, advantageous methodologies in terms of selectivity, availability of starting materials, operational simplicity, functional-group tolerance, environmental sustainability and economy are in constant demand. In this context, the development of new cross-coupling reactions that use catalysts based on inexpensive and non-toxic metals is attracting increasing attention. Similarly, efficient processes that do not require a metal catalyst are of extraordinary interest. Here, we report a new and efficient metal-free carbon-carbon bond-forming coupling between tosylhydrazones and boronic acids. This reaction is very general and functional-group tolerant. As the required tosylhydrazones are easily generated from carbonyl compounds, it can be seen as a reductive coupling of carbonyls, a process of high synthetic relevance that requires several steps using other methodologies.
authors.affiliation: Instituto Universitario de Química Organometálica Enrique Moles, Unidad Asociada al C.S.I.C. Universidad de Oviedo, Julián Clavería, 8, E-33006 Oviedo, Spain. barluenga@uniovi.es
authors.forename: José
authors.initials: J
authors.lastname: Barluenga
authors.forename: María
authors.initials: M
authors.lastname: Tomás-Gamasa
authors.forename: Fernando
authors.initials: F
authors.lastname: Aznar
authors.forename: Carlos
authors.initials: C
authors.lastname: Valdés
mesh_terms: D001897:Boronic Acids / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D006835:Hydrazones / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D014105:Tosyl Compounds / Q000737:chemistry*
chemical_list: D001897:Boronic Acids; D006835:Hydrazones; D014105:Tosyl Compounds; D002244:Carbon